The invention relates to a method for generating SR images having improved image resolution, wherein a sequence of individual images comprised of pixels in a non-visible spectral range is recorded and the individual images are combined in an optimization method to form an SR image such that the individual images of the sequence can be modeled as samples of the SR image by means of sampling functions.
Precisely in the non-visible spectral range the image resolution is limited by the detectors of the measuring device used for recording the individual images by virtue of the fact that excessively small detectors and an excessively high number of detectors per measurement area have excessively high manufacturing costs.
The invention is concerned with the issue of how the resolution can be increased, without having to increase the resolution of the detector.
In this respect, a series of methods have been developed which use the movement of a camera or of a detector in order to be able to combine a plurality of recorded individual images to form a higher-resolution SR image.
In this case, the combination is performed such that the individual images can be represented as samples of the SR image by which the optical properties of the measuring device and the detector resolution can be modeled.
The known methods thus use small deviations between the individual images in order to achieve a higher image resolution of the SR image. Problems can occur in this case in practice, however, if the individual images deviate from one another too much, for example because the recorded objects move or vary greatly.
Since in this situation there is the risk of the SR image also having artifacts which are not contained in any of the individual images, in this case the recorded sequence of individual images is usually discarded, and a new sequence of individual images is recorded for creating an SR image.
The invention furthermore relates to a measuring device comprising means for recording a sequence of images in a non-visible spectral range. Such measuring devices are advantageously used for performing the method described.
Krzysztof Malczewski et al.: Super-Resolution Thermal Image Reconstruction, Proceedings of IWSSIP 2010—17th International Conference on Systems, Signals and Image Processing, Jun. 17, 2010, discloses a method in which a high-resolution image is calculated recursively by a difference between calculated and recorded low-resolution images being transformed into the high-resolution image space.
Stephen Won et al.: Sub-pixel registration of moving objects in visible and thermal imagery with adaptive segmentation, Proceedings of SPIE, vol. 8050, May 13, 2011, pages 80501A-80501A-9, discloses methods for segmentation prior to image registration.